Method and device for real-time encoding

Abstract

The present invention relates to a method, an encoder, a computer program product, and a system for real-time encoding. The encoder is arranged to receive movement information about a movement of a camera, the encoder being arranged to encode, in real-time, a video stream acquired by the camera during the movement of the camera, wherein the encoder is arranged to encode based on said movement information. The movement information may be stored in a memory.

What is claimed is: 
     
       1. A method for encoding a video stream including image frames acquired by a camera during a movement of the camera, comprising:
 receiving, before the start of the movement of the camera, from a memory storing predetermined movement information, the predetermined movement information including information about the movement of the camera in a preprogrammed guard tour comprising a predetermined movement pattern between predetermined points at predetermined times, wherein the movement of the camera includes at least one of a pan operation and a tilt operation, wherein the predetermined movement information further comprises a predetermined duration including a start time and an end time of the movement of the camera between each of the predetermined points in the predetermined pattern; and 
 encoding the image frames of the video stream acquired by the camera in real-time during the movement of the camera in the predetermined movement pattern using a temporarily adjusted ratio of inter frames to intra frames in the encoded video stream during the predetermined duration between the start time and the end time of the movement of the camera, 
 wherein the temporarily adjusted ratio comprises a fixed encoding compensation, 
 wherein the encoding uses the temporarily adjusted ratio during the predetermined duration between the start time and the end time of the movement of the camera. 
 
     
     
       2. The method according to  claim 1 , wherein the encoding comprises adjusting said ratio by reducing a number of intra frames at least during the movement. 
     
     
       3. The method according to  claim 1 , wherein adjusting comprises encoding using only inter frames at least during the movement. 
     
     
       4. The method according to  claim 1 , wherein the encoding comprises adjusting said ratio by increasing a number of intra frames during the movement. 
     
     
       5. An article of manufacture including a non-transitory computer-readable storage medium having instructions stored thereon for encoding a video stream including image frames that when executed by a computing device causes the computing device to perform operations comprising:
 receiving, before the start of the movement of the camera, from a memory storing predetermined movement information, the predetermined movement information including information about the movement of the camera in a preprogrammed guard tour comprising a predetermined movement pattern between predetermined points at predetermined times, wherein the movement of the camera includes at least one of a pan operation and a tilt operation, wherein the predetermined movement information further comprises a predetermined duration including a start time and an end time of the movement of the camera between each of the predetermined points in the predetermined pattern; and 
 encoding the image frames of the video stream acquired by the camera in real-time during the movement of the camera in the predetermined movement pattern using a temporarily adjusted ratio of inter frames to intra frames in the encoded video stream during the predetermined duration between the start time and the end time of the movement of the camera, 
 wherein the temporarily adjusted ratio comprises a fixed encoding compensation, 
 wherein the encoding uses the temporarily adjusted ratio during the predetermined duration between the start time and the end time of the movement of the camera. 
 
     
     
       6. An encoder for encoding a video stream including image frames acquired by a camera during a movement of the camera, comprising:
 the encoder being configured to receive, before the start of the movement of the camera, from a memory storing predetermined movement information, the predetermined movement information including information about, the movement of the camera in a preprogrammed guard tour comprising a predetermined movement pattern between predetermined points at predetermined times, wherein the movement of the camera includes at least one of a pan operation and a tilt operation, wherein the predetermined movement information further comprises a predetermined duration including a start time and an end time of the movement of the camera between each of the predetermined points in the predetermined pattern; and 
 the encoder being configured to encode the image frames of the video stream acquired by the camera in the predetermined movement pattern in real-time during the movement of the camera using a temporarily adjusted ratio of inter frames to intra frames in the encoded video stream during the predetermined duration between the start time and the end time of the movement of the camera, 
 wherein the temporarily adjusted ratio comprises a fixed encoding compensation, 
 wherein the encoder is arranged to encode using the temporarily adjusted ratio during the predetermined duration between the start time and the end time of the movement of the camera. 
 
     
     
       7. The encoder according to  claim 6 , wherein the encoder is configured to adjust said ratio by reducing a number of intra frames at least during the movement. 
     
     
       8. The encoder according to  claim 6 , wherein the encoder is configured to encode using only inter frames at least during the movement. 
     
     
       9. The encoder according to  claim 6 , wherein the encoder is configured to adjust said ratio by increasing a number of intra frames during the movement. 
     
     
       10. A digital video camera comprising:
 a camera being configured to acquire a video stream including image frames during a movement of the camera; 
 an encoder being configured to receive, before the start of the movement of the camera, from a memory storing predetermined movement information, the predetermined movement information including information about, the movement of the camera in a preprogrammed guard tour comprising a predetermined movement pattern between predetermined points at predetermined times, wherein the movement of the camera includes at least one of a pan operation and a tilt operation, wherein the predetermined movement information further comprises a predetermined duration including a start time and an end time of the movement of the camera between each of the predetermined points in the predetermined pattern; and 
 the encoder being configured to encode the image frames of the video stream acquired by the camera in real-time during the movement of the camera in the predetermined movement pattern using a temporarily adjusted ratio of inter frames to intra frames in the encoded video stream during the predetermined duration between the start time and the end time of the movement of the camera, 
 wherein the temporarily adjusted ratio comprises a fixed encoding compensation, 
 wherein the encoder is arranged to encode using the temporarily adjusted ratio during the predetermined duration between the start time and the end time of the movement of the camera. 
 
     
     
       11. A system comprising:
 a camera configured to acquire a video stream including image frames during a movement of the camera; 
 an encoder being configured to: 
 receive, before the start of the movement of the camera, from a memory storing predetermined movement information, the predetermined movement information including information about the movement of the camera in a preprogrammed guard tour comprising a predetermined movement pattern between predetermined points at predetermined times, wherein the movement of the camera includes at least one of a pan operation and a tilt operation, wherein the predetermined movement information further comprises a predetermined duration including a start time and an end time of the movement of the camera between each of the predetermined points in the predetermined pattern; 
 encode the image frames of the video stream acquired by the camera in real-time during the movement of the camera in the predetermined movement pattern using a temporarily adjusted ratio of inter frames to intra frames in the encoded video stream during the predetermined duration between the start time and the end time of the movement of the camera, 
 wherein the temporarily adjusted ratio is determined comprises a fixed encoding compensation, 
 wherein the encoder is arranged to encode using the temporarily adjusted ratio during the predetermined duration between the start time and the end time of the movement of the camera; and 
 transmit the encoded video stream via a digital network; 
 a decoder configured to receive the encoded video and decode the encoded video stream into a second video stream; and 
 a client comprising a display configured to display the second video stream. 
 
     
     
       12. The method of  claim 1 , wherein the fixed encoding compensation comprises:
 a fixed encoding compensation applied both in the beginning and end of a movement of the camera. 
 
     
     
       13. The method of  claim 1 , wherein the fixed encoding compensation comprises:
 adding at least one inter frame after an end time of the movement of the camera. 
 
     
     
       14. The method of  claim 1 , wherein the fixed encoding compensation comprises:
 adding an intra frame at the start time of the movement and adding only inter frames after the start time of the movement of the camera. 
 
     
     
       15. The encoder of  claim 6 , wherein the fixed encoding compensation comprises:
 a fixed encoding compensation applied both in the beginning and end of a movement of the camera. 
 
     
     
       16. The encoder of  claim 6 , wherein the fixed encoding compensation comprises:
 adding at least one inter frame after an end time of the movement of the camera. 
 
     
     
       17. The encoder of  claim 6 , wherein the fixed encoding compensation comprises:
 adding an intra frame at the start time of the movement and adding only inter frames after the start time of the movement of the camera.